Hebrews 5:4-6

Amplified Bible

⁴ And besides, one does not appropriate for himself the honor [of being high priest], but he who is called by God, just as Aaron was.

⁵ So too Christ did not glorify Himself so as to be made a high priest, but He [was exalted and appointed by the One] who said to Him,

⁶ just as He also says in another place,